The present invention relates to magnetic disk drive data storage devices, and more particularly to the circuitry used to transmit signals to and from the magnetic data transducers used in such devices.
Designers of computer data storage products continually seek to improve disk drive performance, in terms of more rapid data transmission, increased reliability, and better use of the limited physical space available for the data storage media, data transducing heads and other components. These considerations arise in connection with the electrical circuitry that interacts with the transducing heads and their support and positioning structure. Such circuitry transmits essential data recording, reading and erasure signals to and from the transducers.
This circuitry can take a variety of forms. For example, U.S. Pat. No. 5,012,368 (Bosier et al) discloses multiple leads in the form of wires, extending along one side of a transducer support arm from a lead clip to the transducers. In U.S. Pat. No. 5,276,572 (Kinoshita et al), a flexible printed circuit extends along one side of a stack of transducer support arms towards the magnetic heads supported by the arms. Wires couple individual heads with the flexible printed circuit.
U.S. Pat. No. 5,055,969 (Putnam), assigned to the assignee of this application, discloses a multi-layer flexible circuit, a portion of which is mounted to the transducer support arm parallel to the arm, incorporating a data pre-amplifier 40 and a servo pre-amplifier 42. The circuit further includes a tail portion 32 perpendicular to the arm, requiring EL 90 degree turn or twist in the tail portion.
While these approaches are satisfactory in certain circumstances, present day actuator arrangements featuring thinner, lighter weight planar suspensions for supporting transducers, and frequently involve stacked arrangements of multiple suspensions, and thus raise several needs that remain unmet by presently used circuitry and circuitry support arrangements.
Therefore, it is an object of the present invention to provide a flexible circuit mounted along a transducer suspension that provides improved reliability, simpler installation and better damping characteristics.
Another object is to provide, in connection with actuators incorporating several data transducing heads, several flexible circuit packages associated individually with different transducing heads and mounted in a side-by-side arrangement that improves impedance matching among the circuit packages.
A further object is to provide an improved structure for electrically and mechanically coupling a rigid circuit and flexible printed circuits that extend from the rigid circuit to data transducing heads, to facilitate a space-saving planar orientation of the flexible printed circuits.
Yet another object is to provide an actuator with multiple transducer suspensions in a parallel, stacked arrangement, in which multiple flexible printed circuits are mounted with their major planes parallel to the major planes of the suspensions, to reduce the physical space requirements for the actuator and improve actuator performance.